Telegraph system



June E 1926 A. A. CLOKEY TELEGRAPH SYSTEM Filed y 12, 1920 Po/or/zed.

/M van fa by Mm Patented June 1, .1926.

UNITED STATES PATENT I OFFICE.

ALLISON ANDREW CLOKEY, OE RUTHERFORD, NEW JERSEY, ASSIGNOR To WESTERN ELECTRIC COMPANY, INCORPORATED, F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEGRAPH SYSTEM.

Application filed May 12,

This invention relates to signaling systems and pertains more particularly to systems of simplex telegraphy which employ positive and negative currents.

An object of the invention is to provide a telegraph system of the" above character having means for rendering it possible While a message is being transmitted between two stations, for a receiving operator to instantly break the transmitting circuit and reverse the direction of sending.

Another object is the provision of means, operative when it is desired to reverse the direction of sending, for reversing the relation of the transmitting and receiving apparatus with respect to the line.

For accomplishing the above Objects, the invention provides, at each of the stations, a pair of relays arranged in conjunction with the transmitting and receiving apparatus, whereby, when a current impulse of predetermined polarity and duration is transmitted over the line, these relays will respond to reverse the relation of the transmitting and receiving apparatus at each of the stations with respect to the line.

The drawing shows a Wheatsto-ne transmitter and only so much of the system as is necessary for a clear understanding of the invention. 1

The transmitter 4 comprises 'a pair of con: tact'operating levers 6 and 7, which are revolvably mounted on a member 8. Pivoted at one end of each of these levers are pins, 9 and-10 respectively, which are designed to cooperate-with a tape 5, in which perforations arearranged in such a manner, that the impulses composing a message way be properly transmitted over the line. In order that the pins 9 and 10 may be withdrawn after they have passed through perforations in the tape, a cam mechanism is provided. This cam mechanism comprises a shaft 11, which is driven by means of a motor 12. The shaft of the motor is connected with the shaft 11 by means of a friction clutch, such as shown at 13. Upon the shaft 11, there is secured a series of cams 14, 15 and 16. The first two of these cams are mounted in close proximity to the levers 6 and 7 and serve to withdraw the pins 9 and 10 whenever they pass through a perforation in the tape 5.

1920- Serial No. 380,817.

The other of these cams operates a lever 17, to which there is secured a stepping pawl 18. This stepping pawl 18 is arranged to engage the teeth of a ratchet wheel 19, keyed to a shaft 20. At one end of this shaft 20 is a star wheel 21, which engages a series of feed holes in the tape 5 and serves to eifect the advancement of the tape for each revolution of the cam 16. There is also secured to the shaft 11, an arm 22 which is adapted to be engaged by a latch 23 under the control of a magnet 24.

The levers 6 and 7 upon being actuated, due to the passage of the pins attached to the end thereof through holes in the tape 5,

tuation of the levers 6 and 7 Both of these relays have their arm'atures biased in such a manner as to normally engage the lefthand contact. The first of these relays, however, is designed to respond to current impulses of a negative polarity, while the other responds to current impulses of a positive polarity. In this way current impulses of different polarities may be impressed on the line 28, which extends to a distant station (not shown) Where equipment like that illustrated in the drawing is to'be understood as being present.

There is also connected to the line 28, a pair of polarized relays 29 and 30 respectively, which are designed to respond to current impulses impressed on the line through the actuation of a pair of rotary keys 31 and 32. Relay 29 is arranged in such a manner that a receiving instrument, as indicated by the numeral 33, is normally connected with the line 28 through a sending condenser 34. Although no specific form of recording mechanism has been shown, any of the well-known types of recorders may be used, such as the Siphon recorder, etc. Upon the energization of relay 29 by a current impulse of a polarity opposite to that which previously traversed its windings to position thearmature thereof as shown in the drawing, the armature thereof will be positioned to disconnect the receiving instrument 33 from the line and connect the transmittingfected by the transmission of the message impulses, an impedance coil 35 is connected intermediate the line 28 and the windings of relays 29 and 30. This impedance coil 35 offers a high impedance to current impulses of signaling frequencies, but is of relatively low impedance to .unvaryin direct current applied tothe line due to t e actuationof either of the keys 31 and 32.

The operation of the system is as follows:

Let it be assumed that a message is being transmitted from a distant station over the line 28. The impulses incoming from the distant station will therefore traverse the condenser 34, the left-hand contact of relay 29, and the receiving instrument 33 to ground. It 1s, of course, understood that the transmission of the impulses composing the message is effected by means of transmitting apparatus slmilar to that shown in the lower portion of the figure of the drawing,

and inasmuch as the operation of such apparatus is well known to telegraph experts, and especially since it does not form a partof the present invention, a further description thereof is considered unnecessary.

If the operator at the receiving station des res for any reason to break the transmitt1ng operator and reverse the direction of sendlng, the key 31 would be caused to rotate in the direction indicated by the arrow. The actuation of key 31 in this manner impresses on the line 28, through the windings of -the relays 29 and. 30 and the impedance coil 35, an impulse of a positive polarity, and of such duration as to permit the current in the 11118 at the distant station to rise to its final steady value. This impulse, incoming at the station which was previously transmitting, traverses the windings of relays 30' and 29, which'causes the movement ofthe armatures controlled thereby. Relay 30 in operating closes the circuit including the Winding of the magnet 24,which is thereupon energized. The magnet 24 in operating causes the engagement of the latch 23 with the arm 22, which, as previously brought out, is secured to the shaft 11. The

engagement of the latch 23 with the arm 22 stops the transmitting mechanism.

previously energized in such a manner as to effect the closure of its right-hand contact, which connects the armature of the transmitting relay 2? with the line, is at this instant energized by the current impulse impressed on the line, through the actuation of key 31 at the receiving station for closing its left-hand contact. The closure of the lefthand contact of this relay connects the receiving network thereat with the line 28. At the receiving station, the reverse is however true. That is, relay. 29 is energized for openln'gh its left-hand contact and closing its rig t-hand contact, The closure of the righthand contact thereof connects the armature of relay 27 with the line 28. Relay 30 in operating opens its left-hand contact, thereby breaking the energizing circuit for the magnet 24. The deenergization of magnet 24 al- -lows the latch 23 to disengage the arm 22,

The actuation of this key applies an impulse,

of polarity opposite to that which Was previously applied, through the actuation of the key 31, to the line, thereby causing the positioning of the armatures, controlled by relays 29 and 30, in such a manner as to connect the receiving network with the line and to disconnect the transmitting apparatus from the line. At the original transmitting station, the relays corresponding with relays 29 and 30, have their armatures so positioned that the receiving'instrument 33 is disconnected from the line andthe transmitting mechanism is permitted to transmit the remaining portion of the message. It is thus seen from the previous description that the invention provides means whereby a receiving operator may instantly break a transmitting operatorand reverse the direction of sending with great rapidity.

From the foregoing description it is seen that relays 29 and 30 are of the type known in the art as unbiased non-centered polar remains in whichever position the last energizing impulse of current caused it to assume regardless of the fact that the energizing current has ceased to flow.

Although the invention has been shown and described in connection with a telegraph system of the simplex variety, it is not intended to limit the invention to this particular use, as it is obvious that it may be used in connection with other telegraph or signaling systems without departing from the spirit and scope of the invention.

hat. is claimed is:

-1. A line, transmitting and receiving apparatus at each terminal of said line and means for changing the electrical connection of said transmitting and said receiving apparatus at both terminals to effect a change in the di' action of transmission, said means including a switch at each terminal for controlling circuits from said line to said receiving and transmitting apparatus respectively, one of said circuits being opened at said switch when the other is closed at said switch, relay means controlling said switch, and at all times responsive to line current of character different from the signaling current, and means at each terminal operative at all times for affecting said relay means at both terminals substantially simultaneously and independently of energy of signals.

2. A line, transmitting and receiving apparatus at each terminal of said line and means for changing the electrical connection of said transmitting and said receiving apparatus at both terminals to efi'ect a change in the direction of transmission, said means including a switch at each terminal for controlling circuits .from saidline to said transmitting and said receiving apparatus respectively, one of said circuits being opened at said switch when the other is closed at said switch, relay means at each terminal operative at all times for causin said switches to operate substantially simu tarieously in opposite directions at said terminals, and means at each terminal for controlling both said relay means. I

3. A line, transmitting and receiving apparatus at each terminal of said line and means for changing the electrical connection of said transmitting and said receiving apparatus at both terminals to effect a change in the direction of transmission, said means including switching'means at each terminal for controlling circuits from said line to said receiving and transmitting apparatus respectively, one of said circuits being opened when the other is closed, means including said switching means for impressing current of either polarity at will upon said line, relay means at said terminals responsive to current of one polarity for causing one of said switches to associate the transmitter at that terminal with said line and the other of said switches to associate the receiver at that terminal with said line and responsive to-current of the opposite polarity for reversing these connections.

4. A signaling system comprising a line extending between two stations, receiving and transmitting apparatus at each of said stations, means responsive to a current impulse for automatically reversing the rela tion of said receiving and transmitting apparatus at both stations with respect to said line and means for causing the transmitter thus associated with the line to initiate the transmission of signals independently of an operator.

5. A signaling system comprising a line extending between two stations, receiving and transmitting apparatus at each of said stations, and unbiased non-centered polar relays at said stations respectively responsive to a current impulse for automatically reversing the relation of said receiving and {ransmitting apparatus with respect to said 6. Means for changing the direction of transmission over a signaling line comprising means at each terminal for initiating transmission of current for controlling the association of transmitter and receiver at both terminals with the line independently of signal currents and of the operator at the other station and without the operation of corresponding means at the other terminal for initiating transmission of control current. n 7 The method of changing the direction of transmission over a signaling line and initiating signaling thereover in the reverse direction which comprises controlling the connection of the transmitter and receiver to the line at both terminals from each terminal and controlling the starting of each transmitter at each terminal independently of the operator-at the other terminal Whereby the transmission of signals to the controlling terminal from the controlled terminal may be initiated independently of the operator at the controlled terminal.

8. A telegraph system comprising a pair of terminal stations interconnected by a transmission line, each of said stations including a receiving mechanism, a transmitting mechanism, and an auxiliary transmitting mechanism cooperating with the transmitting mechanism to reverse the direction of transmission over the line.

9. A telegraph system comprising a pair of terminal stations interconnected by a transmission line, each of said stations including a receiving mechanism, a transmitting mechanism, an auxiliary transmitting mechanism, and means cooperating with the auxiliary transmitting mechanism for controlling the lirection of transmission over the line.

10. A telegraph system comprising a pair of terminal stations interconnected by a 5 transmission line, each of said stations ineluding a receiving mechanism, a, transmitting mechanism, an auxiliary transmitting mechanism, and a selective mechanism under the control of the auxiliary transmitting. mechanism for controlling the direction of 10 transmission over the line.

In witness whereof, I hereunto subscribe my name this 10th day of May A. D., 1920. ALLISON ANDREW CLOKEY. 

